Time, origin of the concept of, 159; consciousness of, 164 et seq.; sense of, 164; conception of infinite, 174; measure of, 174 et seq.; psychological process by which its primitive notion is constituted in consciousness, 175 et seq. Time-perception, simple repetition the elements of, 176; the work of attention, 178. Tracy, Destutt de, 80. Tylor, 43, 50, 67, 71, 99, 142, 143. Unconscious activity, 132. Unconscious, the, 224; psychology of the, 226. Unity, idea of, 138; abstract, 141. Unity-type, 143. Utility, 218, 219; law of, 5. Van Ende, 170. Venn, J., 188. _Vera causa_, 181. Verb, the, 78, 97. Vierordt, 163. Visual types, 112, 119 et seq. Vital force, 193. Vocalisation, 61. Vogt, 208. Waitz, 178. Wallace, 217. Ward, 178. Wasps, intelligence of, 14. Weismann, 218. Whitney, 69, 71, 75, 80. Wilks, Dr., 58. Will, the type of causality, 181 et seq. Wizel, Adam, 126. Words, do we think without them?, 40; they pass to autocracy, 102. Writing, 53. Wundt, 103, 149, 161, 162, 163, 176, 189, 196. CATALOGUE OF PUBLICATIONS OF THE OPEN COURT PUBLISHING CO. COPE, E. D. THE PRIMARY FACTORS OF ORGANIC EVOLUTION. 121 cuts. Pp. xvi, 547. Cloth, $2.00 net (10s.). MÜLLER, F. MAX. THREE INTRODUCTORY LECTURES ON THE SCIENCE OF THOUGHT. 128 pages. Cloth, 75c (3s. 6d.). THREE LECTURES ON THE SCIENCE OF LANGUAGE. 112 pages. 2nd Edition. Cloth, 75c (3s. 6d.). ROMANES, GEORGE JOHN. DARWIN AND AFTER DARWIN. An Exposition of the Darwinian Theory and a Discussion of Post-Darwinian Questions. Three Vols., $4.00 net. Singly, as follows: 1. THE DARWINIAN THEORY. 460 pages. 125 illustrations. Cloth, $2.00. 2. POST-DARWINIAN QUESTIONS. Heredity and Utility. Pp. 338. $1.50. 3. POST-DARWINIAN QUESTIONS. Isolation and Physiological Selection. Pp. 181. $1.00. AN EXAMINATION OF WEISMANNISM. 236 pages. Cloth, $1.00 net. THOUGHTS ON RELIGION. Edited by Charles Gore, M. A., Canon of Westminster. Third Edition, Pages, 184. Cloth, gilt top, $1.25 net. SHUTE, DR. D. KERFOOT. FIRST BOOK IN ORGANIC EVOLUTION. Colored plates, and numerous diagrams. (In Preparation.) MACH, ERNST. THE SCIENCE OF MECHANICS. A CRITICAL AND HISTORICAL EXPOSITION OF ITS PRINCIPLES. Translated by T. J. MCCORMACK. 250 cuts. 534 pages. ½ m., gilt top, $2.50 (12s. 6d.). POPULAR SCIENTIFIC LECTURES. Third Edition. 415 pages. 59 cuts. Cloth, gilt top. Net, $1.50 (7s. 6d.). THE ANALYSIS OF THE SENSATIONS. Pp. 208. 37 cuts. Cloth, $1.25 net (6s. 6d.). LAGRANGE, J. L. LECTURES ON ELEMENTARY MATHEMATICS. With portrait of the author. Pp. 172. Price, $1.00 net (5s.). DE MORGAN, AUGUSTUS.